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PERCIST 1.0 PET Response

PERCIST 1.0 (Wahl et al., 2009)

Categorizes FDG-PET treatment response (CMR, PMR, SMD or PMD) from the change in peak standardized uptake value corrected for lean body mass (SULpeak), with an optional James-formula lean body mass helper.

Also searched as: FDG · SULpeak · lean body mass · metabolic response · oncology · tumor response · sul

Baseline SULpeak (hottest measurable lesion)

Peak standardized uptake value normalized to lean body mass; measurable lesions exceed mean liver SUL by 1.5x plus 2 SD.

g/mL
Follow-up SULpeak (hottest lesion, may differ from baseline)
g/mL
All lesion uptake is below mean liver activity and indistinguishable from background

Required for complete metabolic response; measure a background ROI at the site of the original tumor.

New FDG-avid lesion(s) in a pattern typical of cancer
Visible increase in extent of tumor uptake (> 75% TLG increase, no SUL decline)
Another lesion shows > 30% SULpeak or size increase

Blocks a partial metabolic response designation.

Weeks since treatment start

PERCIST recommends reporting the response category with the percentage change and time on therapy.

wk
Sex (for lean body mass helper)
Height (for lean body mass helper)
cm
Weight (for lean body mass helper)
kg
Information
Incomplete input
  • Please provide: baseline SULpeak, follow-up SULpeak.

How this tool works

PERCIST 1.0 measures the hottest tumor voxel region as SULpeak - the mean SUL within a roughly 1 cm3 sphere centered on the most active focus, with uptake normalized to lean body mass. Partial metabolic response requires both a 30% relative and a 0.8-unit absolute fall in SULpeak between the hottest measurable lesion at baseline and the hottest lesion at follow-up (not necessarily the same lesion), with no new FDG-avid lesions and no more than a 30% rise in SUL or size elsewhere. Progressive metabolic disease is a 30% and 0.8-unit rise, a visibly increased extent of uptake (greater than 75% increase in total lesion glycolysis without an SUL decline), or new FDG-avid lesions typical of cancer. Complete metabolic response is resolution of uptake in all lesions below mean liver activity and indistinguishable from background. The percentage change should still be reported as a continuous variable together with the number of weeks since treatment began.

Clinical questions that use this

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